1. Field of the Invention.
The invention relates to a connecting plug for connecting an input/output unit, such as an actuator, a sensor, or the like, to a machine control comprising a central data bus, wherein the input/output unit is to be connected by the connecting plug to a multi-strand electric cable connected to a bus node.
2. Description of the Related Art
It is known to arrange terminal boxes in the data bus of a machine control which terminal boxes are in the form of bus nodes collecting the connecting cables of the connected actuators and sensors. For this purpose, it is necessary to connect each actuator and each sensor by its own cable to the terminal box. This means that a high material expenditure is required, and this also results in very thick cable harnesses which must be collected in corresponding cable pits and channels.
It is an object of the present invention to simplify the connection of sensors and actuators to a central data bus of a machine control.
In accordance with the present invention, this is achieved in that the housing of the connecting plug has a first plug connection for an incoming cable and a second plug connection for an outgoing cable wherein the incoming cable is looped through (connected through) to the outgoing cable and wherein the housing has a connector for the input/output unit, wherein the connector is connected by means of an electronic device arranged in the housing of the connecting plug to the looped-through cable.
By means of the first plug connection, the connecting plug is connected to the incoming cable which is looped through to the second plug connection to which devices can be connected downstream. In this way, several sensors and several actuators can thus be connected in series to the incoming cable wherein these input/output units can also be connected in a mixed arrangement to the same cable. The connecting plug has a connector for connecting it with the correlated input/output unit, wherein the connector is connected by means of an electronic device arranged in the housing of the connecting plug to the looped-through cable. In this way, it is made possible to control by means of the electronic device the connector in accordance with the connected input/output unit. The user can thus employ the same connecting plug for connecting sensors as well as for connecting actuators. This simplifies mounting.
The intelligent connecting plug recognizes by means of the electronic device integrated into the housing the connected unit and correspondingly connects the unit to the individual lines of the cable to the data bus.
In a first embodiment, the housing of the connecting plug is configured like a plug strip. In this connection, the connection to the connected input/output unit is embodied as a cable extending from the housing. The free outer end of the cable comprises a multi-terminal connecting plug for realizing a connection to the input/output unit. The plug is preferably a multi-terminal valve plug and serves for connecting an actuator unit which is in the form of a valve terminal. By configuring the free end of the connecting cable with a corresponding configuration of the multi-terminal valve plug, valve terminals of different manufacturers can be connected with the system.
It can be advantageous to configure the connector for the input/output unit as a plug connector which is mounted and secured in the housing so that the connecting plug can be plugged, without requiring an external connecting cable, directly onto the housing of an input/output unit such as a sensor or an actuator.
Advantageously, the electronic device in the housing of the connecting plug is cast in, particularly seal-tightly potted or embedded, so that even under rough environmental conditions a mechanical damage of the electronic device or unwanted effects caused by dirt, solvents or the like can be safely prevented. In this connection, the material which is used for potting the electronic device in the housing is preferably identical to the housing material of the connecting plug.
The connecting plug which is embodied correspondingly solidly, has a mounting opening which can be integrated within the housing. By means of the mounting opening, the connecting plug can be mechanically secured while at the same time the connected cable is fixed stationarily.
The embedded (cast-in) electronic device is provided with a light-emitting diode (LED) which serves as an optical display or indicator in the wall of the plug housing. By means of the electronic device, it is possible to perform a self-diagnosis of the connected input/output unit and to monitor the incoming and outgoing cables.
In order to be able to take into consideration different mounting situations, the plug connector in a side view is T-shaped or Y-shaped wherein the plug connector forms the bottom of the T or the Y and the plug connections are provided at the ends of the transverse beam of the T or the two upper ends of the Y.